503 errors that are not backend timeouts? ( Wordpress )

I have a Wordpress install that gets occasional 503 errors on HTTP POST urls. And I need to find out what's causing these. Any help in tracking those down would be appreciated.

Looking at my logs I can see that the 503 errors are not timeouts. I've got the backend timeouts set to 5 minutes and Varnish log shows the 503 errors being sent between 5 to 40 seconds into the script run.

Can anyone tell me why Varnish would return a 503 error to the client besides after a backend timeout? ( HTTP GETs are not affected )

2012/7/27 Kervin L. Pierre <kervin [at] adevsoft>: > I have a Wordpress install that gets occasional 503 errors on HTTP POST urls. And I need to find out what's causing these. Any help in tracking those down would be appreciated. > > Looking at my logs I can see that the 503 errors are not timeouts. I've got the backend timeouts set to 5 minutes and Varnish log shows the 503 errors being sent between 5 to 40 seconds into the script run. > > Can anyone tell me why Varnish would return a 503 error to the client besides after a backend timeout? ( HTTP GETs are not affected )

Thanks for the link. I actually ran into this ticket earlier put didn't read it in detail. And you're right, this is the issue I'm facing, thanks!

It's disappointing to see the bug was closed as 'invalid' though. This seems to be a potentially very common bug. I'm not doing anything 'exotic' in this install. And the workaround seems to be "don't let varnish touch HTTP POSTs".